The KRISS Vector MK1 Modular Rail is designed as bolt on hand guard extension for your KRISS Vector CRB and is made from hard anodized aluminum alloy. The rail’s shape follows the form factor of the KRISS Vector’s body and is milled to reduce weight while still maintaining a rigid structure for support. The KRISS Vector MK1 Modular Rail features female threading along the three o’clock six o’clock and nine o’clock surfaces for the attachment of the included KRISS Vector Picatinny Side Rail Kit which comes pre-installed on the handguard. The MK1 Modular Rail mounts directly to the body of your KRISS Vector and will fit on GEN II models. – Overall Length: 8.375 / 213mm – Overall Width: 2 / 50.8mm – Internal Width: 1.72 / 43.7mm – Internal Height: 2.625 / 66.7mm – Weight: 8oz / 226.7g